White area after rebuild.

Hi !
My scene looking good first but i rebuild after some change.
Now i have white area, i rebuild 2 times…
Any idea ?
Unreal 4.26 +gpu lightmass.


Did you get any errors or warnings when you built the lighting? Looks like those meshes likely have bad lightmap UV’s

Yes, some error in the output log. But strangly the first build was nice.
I just change some furnitures, rebuild and now i have those issue and flickering object.

I have the exact same problem.

The scene has no UV problems, it has worked fine in 4.25.4 with the old GPU Lightmass, but we had to move to 4.26 to be able to use Virtual texture, but now a LOT of objects have this problem.

These two sofas are the exact same model with the exact same uvs…

The maps load correctly while building: